A conventional common mode noise filter will be described with reference to the accompanying drawings. FIG. 11 is an exploded perspective view of a conventional common mode noise filter. As illustrated in FIG. 11, the conventional common mode noise filter includes a plurality of stacked insulating layers 1a to 1g, first coil 2, and second coil 3. First coil 2 is configured by connecting spiral first coil conductor 4a to spiral second coil conductor 4b. Second coil 3 is configured by connecting spiral third coil conductor 5a to spiral fourth coil conductor 5b. The coil conductors (first coil conductor 4a, second coil conductor 4b) that constitute first coil 2 and the coil conductors (third coil conductor 5a, fourth coil conductor 5b) that constitute second coil 3 are alternately disposed. First coil conductor 4a and third coil conductor 5a are magnetically coupled together to form first common mode filter unit 6. Second coil conductor 4b and fourth coil conductor 5b are magnetically coupled together to form second common mode filter unit 7. By connecting first common mode filter unit 6 to second common mode filter unit 7 in series, the conventional common mode noise filter reliably provides a high common mode impedance, removing common mode noise.
For example, PTL 1 is known as a prior art document information regarding the invention of this application.